Physical Characteristics:
Bats are unique among mammals because their forelimbs are specialized for
true flight. Flight membranes, which are actually extensions of the skin
of the back and belly, connect the body with the wings, legs, and tail.
Unlike birds, bats use both legs and wings during flight. Other modifications
for flight include greatly elongated fingers to provide support for the
wing membrane, a keeled sternum for the attachment of the enlarged flight
muscles, and fusion of some vertebrae. The membrane extending from the tail
to the hind legs is known as the interfemoral membrane. The pelage of the
large hoary bat is composed of a mixture of yellowish-brown, deep brown,
and white hairs. Most of the dorsal hairs are tipped with white, thus giving
this bat a distinct silver (hoary) frosting. The margins of the broad,
rounded ears are rimmed with dark brown or blackish-brown. A distinct patch
of whitish fur is present near the base of the forearm. The dorsal surface
of the interfemoral membrane is densely furred.

The hoary bat is the most widely distributed bat in North America (
Tuttle, 1988). It ranges from southern Mexico throughout most of the United States
and into Canada. It is apparently uncommon in the southern part of the United States
and is absent from peninsular Florida. The hoary bat is a tree-roosting bat. During
the summer, it is "normally" found in areas of northern coniferous forests where it
roosts in hemlock, spruce, and fir trees. It migrates to warmer regions in the fall.

Range Maps

North America

Great Smokies

Great Smoky Mountains National Park:
The hoary bat is widely distributed but difficult to observe
because of its solitary tree-dwelling habits. Rick Varner, a
biologist technician in the park, reported observing a live
hoary bat in a small cave in Whiteoak Sink in 1988-1989
(Varner, personal communication, 1993). On September 24, 1992,
a male hoary bat was found dead at the home of Lucinda Ogle on
Ski Mountain Road in Gatlinburg. This property is adjacent to
the park boundary.

The hoary bat is usually found in forested areas where it roosts in trees. During the
summer, it is normally found in areas of northern coniferous forests where it roosts
in hemlock, spruce, and fir trees. In the fall, it migrates to warmer regions.

Reproduction
The hoary bat mates during the autumn migration but implantation
is delayed until spring. An average of 2 young are born between
mid-May and early July.

Longevity
The hoary bat may live 12 to 14 years in the wild.

Terrestrial Ecology
The senses of sight and hearing are well developed in bats.
Since most bats become active near dusk and are active much of the
night, sight is of little importance in navigation and in the
capture of prey. Instead, they use echolocation, a system somewhat
similar to radar. They emit ultrasonic calls far above the range of
human hearing that are reflected from objects ahead of them. They
hear the echoes and are able to avoid obstacles and find food in total
darkness. Different species can be distinguished by differences in the
structure of their echolocation calls (Fenton and Bell, 1981).

The hoary bat is a strong and rapid flier. It is usually the last bat
to appear in the evening since it does not usually leave its roost until
well after sundown. During feeding maneuvers, the tail and wing membranes
are used to capture and restrain prey. Some insects are captured by the
tail membrane, which forms a pouch-like compartment. The bat must bend
its head forward in order to grasp the insect with its teeth and take
it into its mouth. Sometimes the bat may use its mouth to capture an
insect from its wing.

Eleven species of bats have been recorded in the park and all feed exclusively
on insects. During the colder months when flying insects are unavailable,
bats must either hibernate or migrate to warmer areas. Eight of our bats
are known to hibernate. Only three - the red bat, hoary bat, and the
silver-haired bat - are migratory. Bats have been seen flying over the
park during every month of the year. When flying during the winter, however,
they do not feed.

Predators and Defense
No predators recorded from the park.

Parasites
None recorded from the park.

Transmittable Diseases
Bats are capable of transmitting two diseases to humans - rabies
and histoplasmosis. Histoplasmosis is a disease caused by inhaling
dust that contains contaminated spores. Tuttle (1988)
stated: "Less than a half of 1 percent of bats contract rabies, a frequency no
higher than that seen in many other animals. Like others, they die
quickly, but unlike even dogs and cats, rabid bats seldom become
aggressive." Bats do not attack when they get rabies; they just lie in
one place. Although it is rare for humans to contract rabies from
infected bats, persons handling them should be aware of this possibility.